Current industry and military methods of attaching elements to a surface under or above water are varied. Some of the most common methods of attachment include the use of adhesives, magnets, fasteners, stud guns, welding, and suction devices. However, each of these methods has limitations.
Adhesives are typically mixtures in the liquid or semi-liquid state that adhere or bond items together. Surfaces to be joined must be clean for the adhesive to bond. Usually, submerged objects are not clean and are difficult to clean properly while submerged. Therefore, adhesives are an impractical method for underwater attachments. Furthermore, most adhesives take 24 hours to fully cure thereby causing work delays. There are some two-part epoxies that can cure in as little as five minutes, but they require refrigerated storage and are more volatile. The quicker the curing time, the more reactive the ingredients thereby creating hazardous material concerns.
Magnets can provide extremely strong bonds. However, they only attach to ferrous materials. Thus, wooden, plastic, concrete, ceramic, and fiberglass objects are excluded from this attachment method.
Fasteners provide a mechanical means to attach two objects together with nails or screws. Above the water, this approach is fairly easy to implement with just a few tools, but can be time intensive. Using this method to attach objects underwater can be not only time intensive, but also nearly impossible. If the person trying to making the attachment is wearing diving gloves or if the water is very dirty or turbulent, it may not be possible to use this attachment method. Additionally, underwater power tools are limited to pneumatics and require topside air supplies.
Stud guns create strong attachment points on metal, wood and concrete, but have strict handling requirements because they generate projectiles. They also do not work well for plastic, fiberglass and ceramics which often split or shatter with the force of the projectile.
Suction devices can be used to attach objects on flat smooth surfaces like glass or rough surfaces like brick. Basic suction cups work well on smooth surfaces like glass; however, a continuous vacuum needs to be pulled when using suction devices on rough surfaces. Pulling a continuous vacuum requires a pump, hoses, and a power source. Further, all suction cups leak to some degree.